Abstract: A method for improving the cytotoxic effect of Ecteinascidin-743 (ET-743) or an analog thereof on a tumor cell population in a patient the method including administering to the patient, sequentially or simultaneously, a therapeutically effective combination of a composition including ET-743 and an amount of a composition including a PARP-1 inhibitor effective to increase the cytotoxic effect of ET-743 on the tumor cell population. Anti-tumor compositions containing a therapeutically effective amount of ET-743 and an amount of a PARP-1 inhibitor effective to increase the tumor cytotoxicity of the ET-743 are also presented.

Abstract: The present invention discloses a novel single nucleotide polymorphism (SNP) in the isolated 5? tandem repeats of the thymidylate synthase (TS) gene and methods for its use. The novel SNP, located in the 12th nucleotide of a 28 bp third tandem repeat (3R) of the TS gene, substitutes a C for a G, and is the variant form of the repeat. Subjects with the wild-type form of 3R have greater transcription of the TS gene than subjects with the variant form. The invention also reveals that a six base pair deletion in the 3? region of TS (?6 bp/1494) indicates mRNA instability and thus reduced production of TS. In diseased tissue, such as cancer, reduced production of TS is beneficial because it prevents the cancerous cells from growing and spreading. Analysis of either polymorphism or both together allows for prediction of a subject's response to chemotherapeutic and anti-cardiovascular disease treatments because both diseases are related to TS levels in a subject.